Switch



Feb. 17, 1948. H. w. GRAYBILL ETAL SW'ITCH Filed Dec. 11, 1945 2Sheets-Sheet 1" INVENTORS Howard M 6/0 y/Y/ WITNESSES:

and Paul 0/550/1 ATTOR Y Patented Feb. W, 1948 UNITED STATES PATENTOFFICE amass swrrcn Howard w. Graybill and Paul Olsson, Wilkinsburg; Pa,assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., 1;corporation of Pennsylvania Application mama. 11, 1943, Serial No.513,852.

7 Claims. (Cl. 200-48) movement about a transverse axis to and away 1from a position where it is disposed in proximity to one or more linecontacts, and the blade is also mounted for rotation about itslongitudinal axis when in proximity to the line contacts, to move intoand out of high-pressure engagement with the contacts. It has beencustomary to conduct current from the switch blade to the line terminaladjacent the blade pivot, by means of flexible shunt. One method ofavoiding this is disclosed in the aforesaid Rawlins application, andcomprises the provision of a second set of high-pressure contact jaws onthe line terminal adjacent the blade pivot to be engaged with highpressure bythe same movement of the blade which causes high-pressureengagement with the other line contact remote from the blade pivot.

One object of this invention is to provide novel means for conductingcurrent in a switch of the type described, from the switch blade to theline terminal located adjacent the blade pivot.

More specifically, it is an object of this inven-' tion to provide anovel hlgh-pressure-contact current path in a switch of the typedescribed, be-. tween the switch blade and line terminal locatedadjacent the blade pivot, wherein the high-pressure contacting surfacesare entirely enclosed or covered at all positions of the blade, togetherwith provisions for relieving at least a part of the contact pressureduring pivotal movement oi the switch blade. I

Another object of this invention is simply to provide a novel form ofhigh-pressure contact for electric switches.

' become more apparent upon consideration ofthe following detaileddescription of a preferred embodiment thereof, when taken in connectionwith the attached drawings in which:

Figure 1 is a side elevattcnal view of a disconnecting switchconstructed in accordance with this invention:

Fig. 2 is a top plan view oi the switch shown in Fig. 1;

Fig.3 is an enlarged transverse section through the switch shown in Fig.1, taken substantially on the line III-III thereof and Flg. 4 is also anenlarged transverse section through the switch shown in Fig. 1, buttaken substantially on the line IV-IV thereof.

Th particular switch illustrated may be mounted on a supporting base 2,such as a channel iron or the like, and includes spaced insulators Stillanother object of this invention is to provide a simplified bearingsupport for one end of a rotatable blade-actuating insulator.

A more particular object of this invention is to provide certainimprovements in high-pressure contacts per se to render them moreeflicient in operation and to have a longer life.

4 and 8 rigidly secured to mountings 8 on support '2, for example as bybolts Ill. The insulator 4 has secured to the free end thereof aterminal strap l2 of copper or other good electrical conductingmaterial, for example as by bolts l4. The terminal strap l2 has one endthereof angularly directed as at It in a direction outwardly ofinsulator 4, to form a stop flange. for a purpose to be described,Agenerally U-shaped line contact ll, preferably of some wear resistantgood electrical conducting material, such as a copper alloy, for examplea beryllium-cobalt-copper alloy, is adapted to be secured on terminalstrap 82 in electrical conducting relation therewith, by bolts l4 and 20extending through apertures provided in the bight portion oi thecontact. One of the securing bolts l4 also acts to secure an arcing horn22 in conducting relation to terminal strap l2. The outer end of arcinghorn 22 is bent at an angle as shown at 24. As clearly shown in Figs. 1and 2, terminal strap 12, at the end opposite stop fiange [6, extendsoutwardly of insulator 4 for the connection oi a line conductor thereto.

An operating insulator 26 is provided at one end with a short stub shaft30, adaptedto be rotatably mounted in a bearing 28 mounted on support 2.An operating crank 32, which may be connected to suitable operatingmechanism, or directly actuated manually. if desired, is secured to stubshaft 30 and insulator 26 for actuating the insulator. A supporting orbracing frame 24 is adapted to be secured to the outer end of insulator6, as by screws and has at one end thereof an intezrally'forniedterminal pad 33 for the connection of a line conductor I thereto. Framemay be of any desired melhese and other objects of this invention will66 tallic material and is preferably cast to provide opposite sideplates 38, and integral open webbing 31 Joining the side plates atselected points, with reinforcing flanges 38 positioned adlacent the endof frame 34 nearest to rotatable insulator 28. The ends 38 of the sidesof frame 34 are extended to be substantially in alignment with the axisof rotation of insulator 26, and are transversely apertured forcooperation with integral apertured lugs 48 provided on a rigid membercomprising a hollow blade supporting housing 42. It wilibe seen byreference to Figs. 2 and 4, that the lugskfll on blade supportinghousing 42 are each positioned at the same side of extensions 38 onframe 34, or, as shown in Fig. 2, lugs 48 on the blade supportinghousing are each positioned below one extension 38 on the sides of frame34. The reason for positioning lugs 48 offset to one side of extensions38 of the supporting frame, is that since both the frame and bladesupporting housing are preferably cast in form, the lugs 48 andextensions 38 will be relatively rigid and, therefore, in order toobtain good contact between the contact portion of at least one of lugs48 and contact means comprising the confronting face of its adjacentextension 38, it is necessary that a force exerted on these parts, whichtends to move the parts in opposite directions, will force both lugs 48into engagement with their respective frame extensions 38, Contactpressure between lugs 48 and frame extensions 38 is obtained by mountinggenerally cup-.

shaped spring washers 58, on the pivot bolts 46 for each lug and frameextension, so that when the nut 48 of the pivot bolt is drawn tightlyand locked in position by a cotter pin 49, each spring washer will exerta force tending to move the housing 42 and frame 34 in oppositedirections, to thereby cause engagement of lugs 48 and frame extensions38 with a high pressure. If desired, the confronting faces of lugs 48and frame extensions 38 may be coated-for example by electro-deposition,with a. layer of a good electrical conducting material 44. such forexample as silver, to thereby provide a low resistance current pathbetween the frame 34 and blade supporting housing 42. It will beobserved that even though the spacing of lugs 48 does not exactlycorrespond to the spacing of frame extensions 38, at least one lug andframe extension will be urged into good high-pressure contact, and ithas been found that this is sufllcient to carry the current from frame34 to blade housing 42.

The switch blade 82 proper. is preferably tubular in form and the innerend thereof extends through an opening provided in hollow blade support42, and is provided within the blade support with an actuating fork 54secured to theinner endof the blade. Switch blade 52 is rotatablymounted in one wall of blade housing 42 and in an outer wall definingthe outer end of a hood portion 88 integral with the blade housing 42,so that the blade may be. rotated substantially about its ownlongitudinal axis. An angularly extending drive crank 38 is provided forthe purpose of actuating blade. 82 both in a rotatable fashion about itslongitudinal axis, and in a pivotal manner about pivot bolts 46 forblade support housing 42. The drive crank 56 is integral with a capplate 51 secured to the free end of rotatable insulator 28, for exampleas by bolts 58. The portion of the actuating crank structure adjacentplate 81 is provided with a slot 88 for receiving an integral projection82 on frame 34. A pivot pin 84 is adapted to be freely positionedthrough apertures provided in the drive crank structure including itscap plate 51, and through an aperture provided in frame extension 62.Frame 34 thus provides a. bearing for the free end of rotatableinsulator 26 which also acts to brace the insulator at its outer end.

Rotatable drive crank structure 56 is provided with a substantiallyspherical portion 88 adapted to be positioned at the point where thedrive crank structure passes through an opening 88 provided in the bladesupporting housing 42. The outer end of drive crank 56 is provided witha roller 18 adapted to be received in a groove 12 formed on the innerwall of blade supporting housing 42, as in the aforementioned R'awlinsapplication.

The outer end of switch blade 52 is flattened at 14 to form a portionhaving a width somewhat greater than the space between the sides ofcontact 18, so that when positioned transversely of contact l8,side-edge portions of blade part I4 will be in high-pressure wedgingengagement with contact l8. Preferably, an arc and wear resistantU-shaped contact piece 15 is porvided for the end 14 of the blade, withthe contact piece having the leg portions thereof telescoped over theside edges of part 14 of the blade, and preferably being channel-shapedin section so as to receive such edges within the leg portions of thecontact strip 15. The contact strip 15 may be secured to the outer endof the blade in any desired manner, such for example as by soldering theleg portions thereof to the side edges of the blade. Preferably,U-shaped contact strip 18 is secured to blade end I4 with the bightportion thereof spaced from the free end of the blade, and provided withan aperture for receiving the inner end of a rod-like arcing horn 16.The inner end of horn I8 may be threaded, and secured to contact strip15, for example, as by the nuts 18.

The hood portion 88 of contact supporting housing 42 is provided with acover 82 for the open side thereof, to completely enclose the spacebeneath hood portion 88 and the portion of switch blade 52 which liestherein. Cover 82 may be secured in position by any desired means, suchfor example as by machine screws 84. Hood portion 88 is provided beneaththe same with an integral longitudinally-extending contact portion 86(Fig. 3), adapted to be engaged by contact means comprising a.substantially spiral-shaped contact spring 88, suitably secured at oneend to switch blade 82, for example as by bolts 88. Contact spring 88may .be of any desired resilient material which is also a good conductorof electricity, such as, for example, a copper alloy similar to thatused for line contact l8.

In the closed circuit position of the switch, the parts occupy thepositions shown in the drawing, that is, blade portion 14 is positionedsubstantially transversely of the sides of line contact l8 so as to bein high-pressure engagement therewith. Similarly, the spiral contactspring 88 on the blade beneath hood 88, is in pressure engagement withcontact portion 88 integral with blade supporting housing 42. Theelectrical circuit through the switch may then be traced from terminalstrip [2 to line contact l8, and to switch blade 52 by the high-pressureengagement of the line contact with contact strip 18 on the blade: thecircuit proceeds through the switch blade to its spring contact 88 andtocontact portion 88 by virtue of the high-pressure engagement of thesetwo parts; then through blade supporting housing 42 and its lugs 40 toextensions 38 of frame 3t, by virtue of the high-pressure'engagement oflugs 40 and frame extensions 38; thence through the frame to theotherline terminal 33,

In the operation of the switch described above, when it is desired toopen the switch, insulator 26 is rotated in a counterclockwise directionas viewed in Fig. 2. The initial movement of the rotatable insulatorcauses drive crank 56 to carry actuating fork 54 of the blade with it,and thereby cause rotation of the blade about its longitudinal axis toposition portion I4 of the blade at an acute angle with respect tocontact l8. This rotation of the blade in a counterclockwise directionas viewed in Fig. 3, will also at least partially release contact spring38 from pressure engagement with contact portion 86. During this initialrotation. of the blade, there will be no pivotal movement about pivotbolts 46, because the roller '50 on the actuating crank travels in thestraight end portion 63 of slot 12 which is disposed in the plane ofthis initial movement of roller 70. However, after contact pressure hasbeen released at line contact iii, the roller will enter the inclinedportion of slot 12 and thereby cause movement of blade-supportinghousing 42 and with it the blade 62, ina clockwise direction as viewedin Fig. 1, to move the blade to a position spaced away from line contactl8. The open position of the switch blade may be defined by anadjustable stop bolt 13 mounted in frame 34, in a position to beengageabie with an indentation 'Ii provided in blade-supporting housing42. During pivotal movement of blade 52 away from contact l8, actuatingcrank 56 has but a small component of motion transversely to fork 5t,and hence very little rotation of the blade about its longitudinal axiswill occur. When it is desired to close the circuit, insulator 25 isrotated in the opposite direction. This first causes pivotal movement ofthe blade and its blade support about pivot bolts 48, until the outerend of the blade reenters contact l8. At this time the roller on theactuating crank will be just entering-the straight end portion of slot12 in the housing, so that continued rotation of insulator 26 in thesame direction will not cause any pivotal movement of the blade and itshousing about pivot bolts 46, but will cause only rotation of blade 52about its longitudinal axis to cause the portion M and contact spring 88to be rotated into high-pressure contact with line contact l8 andcontact projection 86 of the housing, respectively. During pivotalmovement of blade 52 adjacent line contact i8, arcing horn 16 thereonwill remain inengagement with fixed arcing horn 22. Stop flange i8prevents excessive movement of blade 52 when the closing operation takesplace very rapidly. I

From the foregoing, it is believed apparent that this invention providesa novel arrangement for conducting current from one line terminal 33 toswitch blade 52. It will be observed that this current path includeshigh-pressure contact between lugs 40 and frame extensions 38 which arealways in engagement at all positions of the switch. This current pathalso includes highpressure contacts 38 and 38 which are engaged underhigh-pressure only at the final closed posi-' tion of the switch.However, high-pressure contacts 88 and 88 are totally enclosed so thatthe current path from terminal 33 to the switch blade is entirelyprotected at all times. The particular means for obtaining high-pressurecontact between the biade and its supporting housing 42 in response torotation of the blade, while especially adapted for the particularapplication illustrated. may find certain desirable cooperation in othertypes of switches, as well. There is also disclosed herein a novelmethod of obtaining high-pressure contact between a pair of rigidmembers pivoted at spaced points, that is, between the supporting frame34 and blade support 42 illustrated, which assures high-pressure contactat least at one of these points. The particular manner of supporting theouter end of rotatable insulator 36 from frame 34, adds to thesimplicity of the switch constituting this invention, and especially tomore economical manufacture thereof. The particular manner of securingan arcing horn to a switch blade illustrated, may also ilnd certainnovel features of cooperation or utility with switches other than theparticular switch disclosed herein.

Having described a. preferred embodiment of the invention in accordancewith the patent statutes, it is desired that the invention be notlimited to this particular embodiment, inasmuch as it will be obvious,particularly to persons skilled in the art that many changes andmodifications may be made in this particular structure without departingfrom the broad spirit and scope or this invention as set forth in thefollowing claims.

We claim as our invention:

' 1. In a switch of the type having a switch blade rotatably mounted onsubstantially its longitudinal axis on a blade support which in turn ispivotally mounted on a line terminal for movement of said blade to andaway from a position, said pivotal mounting of said blade supportincluding a pair of rigid ears on said support and a pair of rigid earson said one terminal, pivot means extending through said ears with theears on said support being positioned in proximity to and oncorresponding sides of the ears on said one terminal, respectively, andresilient means biasing one pair of ears laterally in .one directioninto high-pressure engagement with said other pair of ears.

2. In a switch, a terminal support, a switch blade structure, aplurality of spaced rigid ears on said support, a plurality ofcorrespondingly spaced rigid ears on said blade structure, pivot meansextending through said ears for pivotally mounting said blade structureon said support, the ears on said support being positioned in prox imityto and on corresponding sides of the ears on said blade structure, andresilient means biasing said members laterally in a direction to causeengagement under pressure of said ears.

3. In a switch, a terminal support, a. switch blade structure, aplurality of spaced rigid ears on said support, a; plurality ofcorrespondingly spaced rigid ears on said blade structure, pivot meansextending through said ears for pivotaily mounting said blade structureon said support, the ears on said support being positioned in proximityto and on corresponding sides of the ears on said blade structure, saidpivot means comprising a separate pivot pin for each pair of cars onsaid support and blade structure which are in proximity to each other,and spring washers on each otally mounted on a line terminal formovement.

of said blade to and away from a position wherein an end portion of saidblade lies between the laws 7 cl a line contact. with said end portionor said blade having one transverse dimension greater.

longitudinally of the blade and being secured in overlying relation tothe edges of said blade at said greatest transverse dimension and withthe bight portion of said strip spaced, from the outerv end of saidblade and an arc horn secured to said .bight portion of said contactstrip.

5. In a switch, spaced line terminals, a switch blade mounted on one ofsaid line terminals for rotative movement substantially about. itslongi. tudinal axis into and out of high pressure engagement with acontact on the other of said termlnals, and for pivotal movement to andaway from a position adjacent said contact, separate bearing meanssupporting said blade for the aforesaid movements, respectively. a rigidmember or conducting material mounted solely for pivotal movement withsaid blade, said member havingone contact portion positioned to engagecontact means onsaid blade at least at the closed circuit position ofsaid switch, said member having a spaced contact portion positioned toengage contact means on said one line terminal, at least at the closedcircuit position of said switch, means causing each of said contactportions to engage its respective contact means under pressure at leastat the closed circuit position of said switch. and said rigid memberhaving housing means movable therewith and with said blade and entirelyenclosing saidone contact portion and said blade contact means at allpositions or said blade, so that none of said contacts are ever exposedto the weather. I

6. A switch, comprising a switch blade rotatably mounted onsubstantially its longitudinal axis in bearing means mounted in a bladesupporting housing, separate bearing means pivotally mounting saidhousing on a line terminal for movement ofsaid blade to and away from aposition in proximity with another line terminal spaced from thefirst-mentioned terminal; actuating means operable in a circuit-openingoperation to first rotate saidblade about said longitudinal-axis out of;high-pressure engagement with said other line terminal and to thereafterpivotally move said blade to a positionspaced away from said other lineterminal, meahs for conducting-current from said one terminal through atleast a part of said housing to said blade at least in the closedcircuit position or said switch, comprising, contacting portions on saidblade and on one portion of said pivotally mounted housing,respectively, said contacting portions being located in said housing sothat the latter completely encloses said contacting portions at allpositions of said switch, cooperating contact surfaces of relativelysmall area on said one terminal and on another portion of said housingarranged so as to be in engagement at all positions of said switch, andmeans for urging said contact surfaces and contacting portions intoengagement under pressure, whereby said current conducting means has nocurrent carrying contact parts exposed to the weather at any position ofsaid switch.

7. A switch, comprising, a switch blade rotatably mounted onsubstantially its longitudinal axis in bearing means mounted in a bladesupporting housing, separate bearing means pivotally mounting saidhousing on a line terminal for movementof said blade to and away from aD081, tion in proximity with another line terminal spaced from thefirst-mentioned terminal, actuating means operable in a circuit-openingoperation to first rotate said blade about said longitudinal axis out ofhigh-pressure engagement with said other line terminal and to thereafterpivotally move said blade to a position spaced away from said other lineterminal, means for conducting current from said one terminal to saidblade at least in the closed circuit position of said switch, comprisingseparable contacts on said blade and on said pivotally mounted housing,respectively, positioned to be moved into and out of highpressureengagement by rotation of said blade relative to said support into andout oihighpressure engagement with said other line terminaLsaid contactsbeing located in said housing so as to be completel enclosed at allpositions of said switch, and contacting portions on said one terminaland said housing, respectively, arranged so as to be in engagement atall positions of said switch, whereby said current conducting means hasno current carrying contact parts exposed to the weather at any positionof said switch.

HOWARD W. GRAYBIIL. 1- PAUL onsson.

REFERENCES CITED The following references are of record in the tile ofthis patent:

UNITED STATES PATENTS

